Proximity heating cell assembly for use in a high-pressure cubic press

ABSTRACT

In an embodiment, a cell assembly for use in a high-pressure cubic press may include at least one can assembly containing a diamond volume. The at least one can assembly may include an end surface in proximity to the diamond volume. The cell assembly may include at least one heating element including a major surface generally opposing and positioned adjacent to the end surface of the at least one can assembly. The at least one heating element may be positioned and configured to heat the diamond volume. The cell assembly may include at least one pressure transmitting medium extending about the at least one can assembly, and a gasket medium that defines a receiving space configured to receive the at least one can assembly, the one or more heating elements, and the at least one pressure transmitting medium.

BACKGROUND

Wear-resistant, polycrystalline diamond compacts (“PDCs”) are utilizedin a variety of mechanical applications. For example, PDCs are used indrilling tools (e.g., cutting elements, gage trimmers, etc.), machiningequipment, bearing apparatuses, wire-drawing machinery, and in othermechanical apparatuses.

PDCs have found particular utility as superabrasive cutting elements inrotary drill bits, such as roller cone drill bits and fixed cutter drillbits. A PDC cutting element typically includes a superabrasivepolycrystalline diamond layer commonly known as a polycrystallinediamond table. The polycrystalline diamond table is formed and bonded toa substrate using a high-pressure/high-temperature (“HPHT”) process. ThePDC cutting element may be brazed directly into a preformed pocket,socket, or other receptacle formed in a bit body. The substrate mayoften be brazed or otherwise joined to an attachment member, such as acylindrical backing. A rotary drill bit typically includes a number ofPDC cutting elements affixed to the bit body. It is also known that astud carrying the PDC may be used as a PDC cutting element when mountedto a bit body of a rotary drill bit by press-fitting, brazing, orotherwise securing the stud into a receptacle formed in the bit body.

Conventional PDCs are normally fabricated by placing a layer of diamondparticles adjacent to a surface of a cemented-carbide substrate and intoa can assembly. The can assembly including the cemented-carbidesubstrate and layer of diamond particles therein may be surrounded byvarious different pressure transmitting media (e.g., salt liners),positioned in a graphite tube having graphite end caps disposed atrespective ends of the graphite tube that forms a heater assembly, andfinally embedded in a cube-shaped gasket medium (e.g., pyrophyllite). Inan HPHT process used to form a PDC, anvils of an ultra-high pressurecubic press apply pressure to the cube-shaped gasket medium and thecontents therein, while the cemented-carbide substrate and layer ofdiamond particles are controllably heated to a selected temperature atwhich sintering of the diamond particles is effected by passing anelectrical current through the graphite tube and end caps.

SUMMARY

Embodiments of the invention relate to proximity heating cell assembliesfor use in a high-pressure cubic press used for fabricating PDCs andmethods of use. In an embodiment, a cell assembly for use in ahigh-pressure cubic press may include at least one can assemblycontaining a diamond volume (e.g., a plurality of diamond particles).The at least one can assembly may include an end surface in proximity tothe diamond volume. The cell assembly may further include at least oneheating element including a major surface generally opposing the endsurface of the at least one can assembly. The at least one heatingelement may be positioned and configured to heat the diamond volume. Thecell assembly may further include at least one pressure transmittingmedium extending about the at least one can assembly. The cell assemblymay further include a gasket medium that defines a receiving spaceconfigured to receive the at least one can assembly, the one or moreheating elements, and the at least one pressure transmitting medium.

In an embodiment, a method may include disposing at least one canassembly within at least one pressure transmitting medium configured toextend about the at least one can assembly. The at least one canassembly includes an end surface and may hold a diamond volume (e.g., aplurality of diamond particles). The method may also include positioninga heating element adjacent to the end surface of the at least one canassembly. For example, the heating element is positioned and configuredto heat a plurality of diamond particles before the substrate whencurrent is passed therethrough. The method may further include enclosingthe at least one can assembly, the heating element, and the at least onepressure transmitting medium within a gasket medium to form a cellassembly.

Features from any of the disclosed embodiments may be used incombination with one another, without limitation. In addition, otherfeatures and advantages of the present disclosure will become apparentto those of ordinary skill in the art through consideration of thefollowing detailed description and the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The drawings illustrate several embodiments of the invention, whereinidentical reference numerals refer to identical or similar elements orfeatures in different views or embodiments shown in the drawings.

FIG. 1A is a cross-sectional view of an embodiment of a cell assemblyenclosing two can assemblies each of which holds a plurality of diamondparticles adjacent to a substrate.

FIG. 1B is an exploded view of the cell assembly shown in FIG. 1A.

FIG. 1C is a cross-sectional view of the cell assembly shown in FIG. 1Aaccording to another embodiment.

FIG. 1D is a cross-sectional view of the cell assembly shown in FIG. 1Aaccording to another embodiment.

FIG. 1E is a cross-sectional view of the cell assembly shown in FIG. 1Dthat details a current path according to an embodiment.

FIG. 1F is a partial, exploded isometric view of electrical contactsconfigured as a heat spreader shown in FIG. 1C that details a currentpath according to an embodiment.

FIG. 1G is a partial, exploded isometric view of the electrical contactsshown in FIG. 1C that details a current path according to anotherembodiment.

FIG. 1H is a cross-sectional view of the cell assembly shown in FIG. 1Aaccording to another embodiment.

FIG. 2 is a partial isometric view of an ultra-high pressure cubic pressconfigured to apply pressure to the cell assembly shown in FIG. 1A andsubstantially simultaneously pass current through the heating elementshown in FIG. 1A to generate diamond-stable HPHT conditions.

FIG. 3A is a cross-sectional view of an embodiment of a cell assemblyenclosing two can assemblies each of which holds a plurality of diamondparticles adjacent to a substrate.

FIG. 3B is an exploded view of the cell assembly shown in FIG. 3A.

FIG. 3C is a cross-sectional view of the cell assembly shown in FIG. 3Aaccording to another embodiment.

FIG. 4A is a cross-sectional view of an embodiment of a cell assemblyenclosing two can assemblies each of which holds a plurality of diamondparticles adjacent to a substrate.

FIG. 4B is an exploded view of the cell assembly shown in FIG. 4A.

FIG. 5A is a cross-sectional view of an embodiment of a cell assemblyenclosing a can assembly which holds a plurality of diamond particlesadjacent to a substrate.

FIG. 5B is an exploded view of the cell assembly shown in FIG. 5A.

FIG. 6 is a cross-sectional view of another embodiment of a cellassembly enclosing a can assembly which holds a plurality of diamondparticles adjacent to a substrate.

DETAILED DESCRIPTION

Embodiments of the invention relate to proximity heating cell assembliesfor use in a high pressure cubic press used for fabricating PDCs andmethods of use. FIGS. 1A and 1B are cross-sectional and explodedisometric views, respectively, of an embodiment of a cell assembly 100.The cell assembly 100 may include one or more resistance heatingelements, such as heating element 104. The heating element 104 mayexhibit a generally disc-like configuration and may comprise graphite orother suitable material having suitable electrical resistanceproperties. In other embodiments, the heating element 104 may begenerally rectangular, generally elliptical, generally annular,washer-like, combinations thereof, or the like. Moreover, while oneheating element is shown, in other embodiments, the cell assembly 100may include two, three, four, or any other suitable number of heatingelements.

The cell assembly 100 may include a pressure transmitting medium. Forexample, the cell assembly 100 may include a first substantially tubularpressure transmitting medium 120, such as a tube made from salt, whichreceives and extends about the can assembly 112. A second substantiallytubular pressure transmitting medium 122 may receive and extend aboutthe can assembly 114. The heating element 104 may be distally disposedadjacent to a distal end of the first substantially tubular pressuretransmitting medium 120. The heating element 104 may be proximallydisposed adjacent to a proximal end of the second substantially tubularpressure transmitting medium 122. Pressure transmitting mediums 120 and122 may be salt, salt and graphite, or any other suitable pressuretransmitting material. As used herein, the term “substantially tubular”encompasses tubular elements having any cross-sectional geometry, suchas a generally circular cross-sectional geometry or other non-circularcross-sectional geometry.

As illustrated, the heating element 104 may divide the cell assembly 100into two regions that receive the can assemblies 112 and 114. Forexample, the can assembly 112 may be received in a first region at leastpartially defined between a proximal anvil electrical contact 124 andthe heating element 104. The can assembly 114 may be received in asecond region at least partially defined between the heating element 104and a distal anvil electrical contact 126. Each can assembly 112 and 114may include a corresponding substrate 112A and 114A (e.g.,cobalt-cemented tungsten carbide substrate) and a corresponding volumeof diamond particles 112B and 114B or other type of diamond volume.Examples of suitable can assemblies and techniques for sealing such canassemblies are disclosed in U.S. Pat. No. 8,236,074 and examples ofsuitable techniques for cleaning diamond volumes are disclosed in U.S.Pat. No. 7,845,438; each is incorporated herein, in its entirety, bythis reference. For example, the can assembly may include a refractorymetal can, as disclosed in U.S. Pat. No. 7,845,438.

Although the embodiments disclosed herein are described in the contextof sintering diamond particles, the diamond particles may be replacedwith another type of diamond volume, such as a preformed polycrystallinediamond table that bonds to the substrate during HPHT processing.Examples of preformed polycrystalline diamond bodies includecarbonate-catalyst sintered polycrystalline diamond bodies orpolycrystalline diamond bodies sintered using metal-solvent catalysts(e.g., cobalt, nickel, iron, or alloys there), which may be leached tosubstantially remove the catalyst therefrom or unleached. For example,U.S. application Ser. No. 12/185,457 filed on 4 Aug. 2008; Ser. No.12/495,986 filed on 1 Jul. 2009; Ser. No. 13/070,636 filed on 24 Mar.2011; and Ser. No. 13/552,052 filed on 18 Jul. 2012 each disclosemethods for manufacturing carbonate-catalyst sintered polycrystallinediamond bodies and compacts that can be fabricated in any of the cellassemblies disclosed herein and/or in which the polycrystalline diamondbodies may be employed as preformed polycrystalline diamond bodies. U.S.application Ser. No. 12/185,457 filed on 4 Aug. 2008; Ser. No.12/495,986 filed on 1 Jul. 2009; Ser. No. 13/070,636 filed on 24 Mar.2011; and Ser. No. 13/552,052 are each incorporated herein, in itsentirety, by this reference.

As shown in FIG. 1A, the diamond particles 112B, 114B within therespective can assemblies 112, 114 may be positioned toward and near theheating element 104 or the heating element 104 may be positioned betweenthe diamond particles 112B and the diamond particles 114B. Accordingly,the heating element 104 may be configured to heat the diamond particles112B and/or the diamond particles 114B before heating the substrate 112Aand/or the substrate 114A of the can assemblies 112, 114. For example,in an embodiment, at least a portion of heat flow from the heatingelement 104 may first pass through the diamond particles 112B or diamondparticles 114B before the heat flow reaches the distal end region of thesubstrate 112A or the proximal end region of the substrate 114A. Such aconfiguration may help create a desired thermal gradient near theheating element 104 and the diamond particles 112B, 114B, thus requiringless time and energy to sinter the diamond particles 112B, 114B.Moreover, such a configuration may allow the heating element 104 to heatboth the diamond particles 112B and the diamond particles 114B atsubstantially the same time; simultaneously, or nearly simultaneously.

Thus, the heating element 104 may be configured to provide heating orgenerally generate heating near targeted locations within the canassemblies 112, 114 and/or to influence heating patterns and/orgradients within the can assemblies 112, 114. Such a configuration mayallow higher sintering temperatures because the heating element 104 canprovide heating to targeted locations without overheating other portionsof the can assemblies 112, 114.

Referring still to FIGS. 1A and 1B, a proximal anvil electrical contact124 may be proximally disposed adjacent to a proximal portion of canassembly 112 and may electrically contact the can assembly 112. A distalanvil electrical contact 126 may be distally disposed adjacent to adistal portion of the can assembly 114 and may electrically contact thecan assembly 114. The proximal and distal anvil electrical contacts 124,126 may be made from steel, titanium, molybdenum, zirconium, TZMmolybdenum metal alloys, combinations thereof, or any other suitableelectrically conductive material. For example, in an embodiment, theanvil electrical contacts 124 and/or 126 may be made from titaniumand/or zirconium. Such a configuration may help reduce heat transfer outof the ends of the cell assembly 100 due to the lower thermalconductivity of the titanium and/or the zirconium compared to steel.Such a configuration may also help reduce the thickness of the anvilelectrical contacts. For example, in an embodiment, the proximal anvilelectrical contact 124 and/or the distal anvil electrical contact 126may exhibit a thickness T of about 0.01 inches, about 0.02 inches, about0.03 inches, about 0.04 inches, about 0.05 inches, about 0.06 inches,about 0.07 inches, about 0.08 inches or about 0.09 inches. In otherembodiments, the proximal anvil electrical contact 124 and/or the distalanvil electrical contact 126 may exhibit a thickness T between about0.01 inches and about 0.1 inches; about 0.02 inches and 0.09 inches;about 0.03 inches and about 0.08 inches; about 0.04 inches and about0.07; about 0.01 inches and about 0.05 inches; or about 0.02 inches andabout 0.04 inches. In other embodiments, the thickness T of at least oneof the proximal anvil electrical contact 124 or the distal anvilelectrical contact 126 may be larger or smaller.

The cell assembly 100 may further include a gasket medium 128 generallyin the shape of a cube. The gasket medium 128 may define a receivingspace 130 that receives the heating element 104, pressure transmittingmediums 120, 122, and can assemblies 112, 114. The receiving space 130(FIG. 1B) may also at least partially receive the proximal and distalanvil electrical contacts 124, 126. A plug 132 may be disposed in anopening (not shown) defined by the proximal anvil electrical contact 124and a plug 136 may be disposed in an opening 138 (FIG. 1B) defined bythe distal anvil electrical contact 126. The gasket medium 128 and theplugs 132 and 136 may comprise any suitable gasket material, such as anymaterial disclosed in U.S. Pat. No. 6,338,754, which is incorporatedherein, in its entirety, by this reference. Another example of asuitable material for the gasket medium 128 and the plugs 132 and 136 ispyrophyllite, which is commercially available from Wonderstone Ltd. ofSouth Africa. In other embodiments, the gasket medium 128 and plugs 132and 136 may comprise different materials, without limitation.

Optionally, the cell assembly 100 may include a heat spreader. A heatspreader is a device or structure that includes one or more geometricfeatures configured to help influence heat transfer. For example, FIG.1C is a cross-sectional view of the cell assembly 100 including adisc-like electrical contact 141 and a ring-like electrical contact 143according to an embodiment. As shown, insulators 163 and 165 may bedisposed between the heating element 104 and the can assemblies 112 and114. In an embodiment, an insulator ring 163 may be disposed between adistal end surface of can assembly 112 and the heating element 104 andan insulator disc 165 may be disposed between a proximal end surface ofcan assembly 114 and the heating element 104. Insulators 163 and/or 165may comprise mica and/or may be made from salt or any other suitablematerial. The disc-like electrical contact 141 may be positioned withinthe central opening of the insulator ring 163 and may electricallycontact the can assembly 112 and the heating element 104. The ring-likeelectrical contact 143 positioned between the can assembly 114 and theheating element 104 and may electrically contact the can assembly 114and the heating element 104. In an embodiment, the insulator disc 165may be positioned within the central opening of the ring-like electricalcontact 143. Optionally, the disc-like electrical contact 141 and/or thering-like electrical contact may further be configured as additionalheating elements. As described below in relation to FIGS. 1E and 1F, bychanging the direction of current flow between the disc-like electricalcontact 141 and the ring-like electrical contact 143 relative to theheating element 104, the direction and/or location of current flowthrough the heating element 104 may be varied and/or controlled.Consequently, the size, intensity, and heating pattern of the heatingelement 104 may also be localized, varied, and/or controlled toinfluence the heating characteristics of the diamond particles 112B,114B.

The cell assembly 100 may include heating elements of varyingconfigurations. For example, FIG. 1D is a cross-sectional view of thecell assembly 100 including three heating elements according to anembodiment. In an embodiment, cell assembly 100 may include heatingelements 102, 104, and 106. At least one of the heating elements 102,104, 106 may exhibit a generally disc-like configuration and maycomprise graphite or other suitable material having suitable electricalresistance properties. In other embodiments, the heating elements 102,104, 106 may be washer-like, generally rectangular, generallyelliptical, generally annular, or the like. Moreover, while threeheating elements are shown, in other embodiments, the cell assembly 100may include one, two, four, or any other suitable number of heatingelements.

The heating element 102 may be proximally disposed adjacent to theproximal end of the first substantially tubular pressure transmittingmedium 120 and the heating element 104 may be distally disposed adjacentto the distal end of the first substantially tubular pressuretransmitting medium 120. The heating element 104 may be proximallydisposed adjacent to the proximal end of the second substantiallytubular pressure transmitting medium 122 and the heating element 106 maybe distally disposed adjacent to the distal end of the secondsubstantially tubular pressure transmitting medium 122.

Similar to FIG. 1A, the heating element 104 may divide the cell assembly100 into two regions that receive the can assemblies 112 and 114. In anembodiment, the can assembly 112 may be received in a first region atleast partially defined between the heating element 102 and the heatingelement 104. The can assembly 114 may be received in a second region atleast partially defined between the heating element 104 and the heatingelement 106.

As shown in FIG. 1D, the diamond particles 112B, 114B within therespective can assemblies 112, 114 may be positioned toward and near theheating element 104 or the heating element 104 may be positioned betweenthe diamond particles 112B and the diamond particles 114B. In anembodiment, the heating element 102 may include a major surface or aproximal surface generally opposing an end surface of the can assembly112 and the heating element 106 may include an opposite major surface orend surface generally opposing an end surface of the can assembly 114.Accordingly, the heating element 104 may be configured to heat thediamond particles 112B and/or the diamond particles 114B before heatingthe substrate 112A and/or the substrate 114A of the can assemblies 112,114. For example, in an embodiment, at least a portion of heat generatedby the heating element 104 may first transfer through the diamondparticles 112B or diamond particles 114B before reaching the distal endregion of the substrate 112A or the proximal end region of the substrate114A. Such a configuration may help create a desired thermal gradientnear the heating element 104 and the diamond particles 112B, 114B, thusrequiring less time and energy to sinter the diamond particles 112B,114B. Moreover, such a configuration may allow the heating element 104to heat both the diamond particles 112B and the diamond particles 114Bat substantially the same time; simultaneously, or nearlysimultaneously. In other embodiments, more than one heating element maybe positioned between the can assemblies 112 and 114. For example, asshown in FIG. 1H, the diamond particles 112B of can assembly 112 may bepositioned near a heating element 104A and the diamond particles 114B ofcan assembly 114 may be positioned near a heating element 104B. Aninsulator ring 163 may be positioned between heating element 104A andheating element 104B. In an embodiment, a disc-like electrical contact141 may be positioned within the central opening of the insulator ring163. Such a configuration may help localize, vary, and/or control thesize, intensity, and heating pattern of the heating elements 104A, 104B.

Referring again to FIG. 1D, the heating element 102 may be positionednear a proximal end portion of the substrate 112A and the heatingelement 106 may be positioned near a distal end portion of substrate114A. The heating element 102 may heat the proximal portion of thesubstrate 112A while the heating element 106 may heat the distal portionof the substrate 114A. In other embodiments, can assemblies 112 and/or114 may be inverted. For example, in an embodiment, can assemblies 112and 114 may be may be inverted such that heating element 102 ispositioned near diamond particles 112B and heating element 106 ispositioned near diamond particles 114B. As a result, heating element 102may be configured to heat diamond particles 112B before substrate 112Aand heating element 106 may be configured to heat diamond particles 114Bbefore substrate 114A. Thus, the heating elements 102, 104, 106 may beconfigured to provide heating or generally generate heating neartargeted locations within the can assemblies 112, 114 and/or toinfluence heating patterns or gradients within the can assemblies 112,114. Such a configuration may allow higher sintering temperaturesbecause the heating elements 102, 104, and 106 can provide heating totargeted locations without overheating other portions of the canassemblies 112, 114.

Referring still to FIG. 1D, the proximal anvil electrical contact 124may be proximally disposed adjacent to the heating element 102 and mayelectrically contact the heating element 102. The distal anvilelectrical contact 126 may be distally disposed adjacent to the heatingelement 106 and may electrically contact the heating element 106.

The cell assembly 100 may be configured such that electrical energy maypass through the cell assembly 100 in a number of different ways. Forexample, FIG. 1E is a cross-sectional view of the cell assembly shown inFIG. 1D that details how an electrical current may pass through the cellassembly 100 according to an embodiment. An electrical current may passfrom an anvil of an ultra-high pressure press (shown in FIG. 2) to theproximal anvil contact 124. From the proximal anvil contact 124, theelectrical current may pass to the heating element 102 and then to thecan assembly 112. From the can assembly 112, the electrical current maythen pass to the heating element 104. The electrical current may thenpass from the heating element 104 to the can assembly 114. From the canassembly 114, the electrical current may pass to the heating element106, through the distal anvil electrical contact 126 and out of the cellassembly 100. As discussed above, the heating elements 102, 104, 106 mayconvert electrical energy into heat to heat the contents of the canassemblies 112, 114.

In other embodiments, the electrical current pathway may pass through aheat spreader. For example, FIGS. 1F and 1G are partial, explodedisometrics views of heating element 104 and the disc-like electricalcontact 141 and the ring-like electrical contact 143 shown in FIG. 1C.In the illustrated embodiment, the disc-like electrical contact 141 mayelectrically contact a proximal portion of the heating element 104 andthe ring-like electrical contact 143 may electrically contact a distalportion of the heating element 104. Like the proximal and distalelectrical contacts, the electrical contacts 141 and 143 may eachcomprise a suitable electrically conductive and temperature-resistantmaterial. For example, electrical contacts 141 and 143 may comprisesteel, titanium, molybdenum, TZM molybdenum metal alloys, combinationsthereof, or any other suitable electrically conductive material.

In the illustrated embodiment, the ring-like electrical contact 143 mayinclude an inner diameter which is greater than an outer diameter of thedisc-like electrical contact 141. The disc-like electrical contact 141may be positioned over the central opening of the ring-like electricalcontact 143. In FIG. 1F, electrical current may pass in a firstdirection from the disc-like electrical contact 141 (+), through theheating element 104 and to the ring-like electrical contact 143 (−).Because the disc-like electrical contact 141 is positioned over thecentral opening of the ring-like electrical contact 143, the electricalcurrent may flow radially outward from the disc-like electrical contact141 through the heating element 104 toward the body of the ring-likeelectrical contact 143. In FIG. 1G, the direction of the electricalcurrent may be reversed such that the electrical current flows in asecond direction from the ring-like electrical contact 143 (+), throughthe heating element 104 and to the disc-like electrical contact 141 (−).Electrical current flowing in the second direction may flow radiallyinward from the ring-like electrical contact 143 through the heatingelement 104 toward the disc-like electrical contact 141. Thus, bychanging the direction of current flow between the electrical contacts141, 143 and/or the size and/or location of the electrical contacts 141,143 relative to the heating element 104, the direction and/or locationof current flow through the heating element may be varied and/orcontrolled. Consequently, the size, intensity, and heating pattern ofthe heating element 104 may also be localized, varied and/or controlledto influence the heating characteristics of the diamond particles 112B,114B.

While the electrical contacts 141, 143 are shown electrically contactingthe distal and proximal portions of the heating element 104, it will beappreciated that the electrical contacts 141, 143 may electricallycontact any portion of the heating elements 102, 104, or 106.

The use of the cell assembly 100 shown in FIG. 1A for fabricating twoPDCs is explained with reference to FIG. 2, which is a partial isometricview of an ultra-high pressure cubic press 200 configured to applypressure to the cell assembly 100 and pass current through the heatingelements (e.g., 102, and/or 104, and/or 106) to generate diamond-stableHPHT conditions. In use, the cell assembly 100 including the canassemblies 112 and 114 therein is placed in a reaction zone of theultra-high pressure press 200. A plurality of anvils 241-246 of theultra-high pressure press 200 apply a selected pressure to respectivefaces of the cell assembly 100. In an embodiment, the anvils 241 and 244may establish electrical contact with proximal anvil electrical contact124 and the distal anvil electrical contact 126. A selected current maybe controllably passed through the heating elements 102, 104, 106 tothereby heat the contents of the can assemblies 112, 114. As discussedabove, the heating element 104 may be positioned between the diamondparticles 112B, 114B of the can assemblies 112, 114 such that theheating element 104 may heat the diamond particles 112B, 114B beforeheating the substrates 112A, and 114A. The heating element 102 may bepositioned toward the proximal portion of the substrate 112A of the canassembly 112 and the heating element 106 may be positioned toward thedistal portion of the substrate 114A of the can assembly 114.

The heating may be sufficient to heat the contents of the can assemblies112 and 114 to about 1200° C. to about 2400° C., to about 1400° C. toabout 2200° C., or to about 1600° C. to about 2000° C., while the anvils241-246 apply a pressure to the contents of the can assemblies 112 and114 of at least about 4 GPa, such as about 5 GPa to about 12 GPa, about6 GPa to about 11 GPa, or about 7 GPa to about 10 GPa. Subjecting thecan assemblies 112 and 114 to the HPHT process results in two PDCs beingformed. One PDC comprises the substrate 112A that is bonded to apolycrystalline diamond table formed from the diamond particles 112Bthat are sintered and another PDC comprises the substrate 114A that isbonded to a polycrystalline diamond table formed from the diamondparticles 114B that are sintered. However, in other embodiments, thecell assembly 100 may be employed for fabricating one, three, or four ormore PDCs of various shapes and sizes (e.g., PDC configurations otherthan the illustrated cylindrical configurations).

Controlling the heating characteristics within the can assemblies 112,114 may help reduce processing time and/or the cost of fabricating PDCs.For example, subjecting the can assemblies 112, 114 to the HPHT processmay cause a constituent of the substrates 112A, 114A, such as cobaltfrom a cobalt-cemented tungsten carbide substrate to liquefy and sweepfrom a region adjacent to the volume of diamond particles 112B, 114Binto interstitial regions between the diamond particles 112B, 114B. Thecobalt may act as a catalyst to promote intergrowth between the diamondparticles 112B, 114B, which results in formation of directlybonded-together diamond grains exhibiting diamond-to-diamond bonding(e.g., sp³ bonding). During the HPHT process, other components of thecemented carbide substrate, such as tungsten and carbon, may alsomigrate into the interstitial regions between the diamond crystals. Thediamond grains become mutually bonded to form a polycrystalline diamondtable, with interstitial regions between the bonded diamond grains beingoccupied by the cobalt (or another suitable catalyst) and othercomponents, if any. In some embodiments, after the matrix ofpolycrystalline diamond is formed, the polycrystalline diamond may beleached to at least partially remove or substantially completely removethe catalyst. In other embodiments, when a carbonate-catalyst materialis mixed with the diamond particles (optionally in the absence of thesubstrates) to form a polycrystalline diamond body, the cell assembly100 is well suited for heating to temperatures sufficient for employingcarbonate-catalyst and/or other non-elemental catalyst materials, suchas greater than about 2000° C.

It is currently believed that subjecting the can assemblies 112, 114 tothe HPHT process may also cause a constituent of one or more can of thecan assemblies 112, 114, such as niobium, to migrate into theinterstitial regions between the diamond particles 112B, 114B such thatthe niobium may become incorporated with the cobalt. When niobiumbecomes incorporated with the cobalt, it can tend to inhibit leaching ofthe cobalt and the leaching process may become more complicated, timeconsuming, and expensive.

By positioning the heating element 104 between the diamond particles112B and the diamond particles 114B, the heating element 104 may shiftthe heating pattern toward the region between the diamond particles112B, 114B and away from the cans of can assemblies 112, 114 in theregion adjacent the diamond particles 112B, 114B, and the substrates112A, 114A. Such a configuration may help reduce concentrations ofchemical constituents of the can assemblies 112, 114 (e.g., niobium)that may become incorporated with the cobalt, thereby, resulting in aleaching process that is simpler, faster, and less expensive.

In other embodiments, cell assemblies may include heating elements ofvarying configurations. For example, proximal electrical contacts may bedisposed adjacent to and/or near the proximal end of the first canassembly 112 and electrically contacting a periphery of the can assembly112. Distal electrical contacts may be disposed adjacent to and/or nearthe distal end of the second can assembly 114 and electricallycontacting a periphery of the can assembly 114. As a result, electricalcurrent may travel from the proximal anvil electrical contact 124, tocan assembly 112, to the heating element 104, to the can assembly 114,and to the distal anvil electrical contact 126. Such a configuration mayhelp provide central direct heating of the diamond particles 112B, 114B.

FIGS. 3A and 3B are cross-sectional and exploded isometric views,respectively, of an embodiment of a cell assembly 300 according toanother embodiment. The cell assembly 300 has many of the samecomponents and features that are included in the cell assembly 100 ofFIGS. 1A-2. Therefore, in the interest of brevity, the components andfeatures of the cell assembly 100 and 300 that correspond to each otheror are otherwise similar in some aspect have been provided withidentical reference numbers, and an explanation thereof will not berepeated. However, it should be noted that the principles of the cellassembly 300 may be employed with any of the embodiments described inrelation to FIGS. 1A-2 and vice versa.

The cell assembly 300 may include one or more resistance heatingelements, such as first and second heating elements 302 and 304. Likethe heating elements of cell assembly 100, the heating elements 302, 304may comprise graphite or any other suitable material. A pressuretransmitting medium (e.g., comprising salt, salt and graphite, etc.),such as first and second tubular liners 308 and 310 may be disposeddistal and proximal the heating elements 302, 304.

Insulators may be disposed between the heating elements 302, 304. Forexample, insulators 362, 364 may be disposed between heating element 302and heating element 304. In an embodiment, the insulators 362, 364 maydivide the cell assembly 300 into two chambers that receive canassemblies 312 and 314. The insulators 362, 364 may comprise micawashers or discs and/or may be made from salt or any other suitablematerial. The can assemblies 312, 314 may be configured similar to canassemblies 112, 114. For example, each can assembly 312 and 314 mayinclude a corresponding substrate 312A and 314A (e.g., cobalt-cementedtungsten carbide substrate) and a corresponding volume of diamondparticles 312B and 314B. As shown, heating element 302 may be positionedin proximity to the volume of diamond particles 312B of can assembly312. A proximal surface of heating element 302 may be generally opposinga distal end surface of the can assembly 312. In an embodiment, theproximal surface of the heating element 302 may be generally parallelthe distal end surface of the can assembly 312. Similarly, heatingelement 304 may be positioned in proximity the volume of diamondparticles 314B of can assembly 314. A distal surface of heating element304 may be generally opposing a proximal end surface of the can assembly314. In an embodiment, the distal surface of the heating element 304 maybe generally parallel the proximal end surface of the can assembly 314.Generally parallel, as used herein, means between two surfaces that formless than about a forty-five degree angle between them. By positioningthe heating element 302 in proximity the diamond particles 312B, theheating element 302 may heat the diamond particles 312B before thesubstrate 312A. Similarly, heating element 304 may heat the diamondparticles 314B before the substrate 314A. Such a configuration may helpprovide preferential heating to the diamond particles 312B, 314B,thereby requiring less energy to sinter the diamond particles 312B,314B. Moreover, such a configuration may allow higher sinteringtemperatures because the heating elements 302, 304 provide sufficientheating to sinter the diamond particles 312B, 314B, without overheatingother portions of the can assemblies 312, 314. In yet other embodiments,one or both of the heating elements 302, 304 may be configured topreferentially heat both the diamond particles 312B and the diamondparticles 314B.

Optionally, the cell assembly 300 may further include one or moretemperature measuring devices configured to measure the temperature ofthe heating elements and/or contents of the can assemblies. For example,in the illustrated embodiment, the cell assembly 300 may includetemperature measuring devices 366, 368 comprising thermocouples thatextend laterally relative to a longitudinal axis of the can assembly 300and electrically contact a portion of heating elements 302 and/or 304.In an embodiment, the thermocouples may include titanium. In otherembodiments, the thermocouples may include steel, nickel, iron,platinum, rhodium, tungsten, metal alloys, or any other suitableelectrically conductive and temperature resistant material for measuringtemperature. In other embodiments, the cell assembly 300 may include atleast one temperature measuring device (e.g., at opposite ends of thecan assemblies 312, 314 and/or cell assembly 300) such that the at leastone temperature measuring device can measure at least one temperaturegradient or optionally more than one temperature in the can assemblies312, 314 and/or the cell assembly 300. In other embodiments, the cellassembly 300 may include at least one temperature measuring devicecomprising at least one of temperature sensors, thermistors,thermostats, resistive temperature devices, noncontact sensors thatmeasure thermal radiant power of infrared or optical radiation,combinations thereof, or other suitable types of temperature measuringdevices. In other embodiments, the temperature measuring devices may beomitted.

The cell assembly 300 may include one or more electrical contacts thatelectrically contact the can assemblies 312 and 314 at the correspondingproximal and distal end regions of the cell assembly. For example, inthe illustrated embodiment, the cell assembly 300 may include aplurality of proximal disc-like electrical contacts 316 disposedgenerally adjacent to a proximal end of the first can assembly 312 andelectrically contacting a periphery of the can assembly 312. A pluralityof distal disc-like electrical contacts 318 may be disposed generallyadjacent to a distal end of the second can assembly 314 and mayelectrically contact a periphery of the second can assembly 314. Theelectrical contacts 316, 318 may be made from titanium, a titaniumalloy, or other suitable electrically conductive and temperatureresistant material. In other embodiments, the proximal and distaldisc-like electrical contacts 316, 318 may be replaced with anelectrical contact that is configured as an annular member (i.e.,washer), a rectangle, or the like. Moreover, the proximal and distalelectrical contacts 316, 318 may include one, three, five, or anysuitable number of electrical contacts. In yet another embodiment, asshown in FIG. 3C, the proximal disc-like electrical contact 316 and/orthe distal disc-like electrical contact 318 may be replaced with anelectrical contact that is configured as a first disc-like electricalcontact 319A, a second disc-like electrical contact 319B, and aninsulator ring 363 interposed between the first and second disc-likeelectrical contacts 319A, 319B. Such a configuration may allow forelectrical current to pass between the first and second disc-likeelectrical contacts 319A, 319B through the central opening of theinsulator ring 363. The first and second electrical contacts 319A, 319Bmay be made from titanium, a titanium alloy, or other suitableelectrically conductive and temperature resistant material. Insulatorring 363 may comprise mica and/or any other suitable material.

Referring again to FIGS. 3A and 3B, a first substantially tubularpressure transmitting medium 320, such as a tube made from salt, mayreceive and extend about the first liner 308, and can assembly 312. Asecond substantially tubular pressure transmitting medium 322 mayreceive and extend about the second liner 310 and can assembly 314. Inan embodiment, the first and second liners 308, 310 and the first andsecond substantially tubular pressure transmitting mediums 320, 322 maybe formed of the same materials. In other embodiments, the first andsecond liners 308, 310 and the first and second substantially tubularpressure transmitting mediums 320, 322 may include one or more differentmaterials exhibiting different pressure transmitting properties.Accordingly, the placement and/or type of materials in the first andsecond liners 308, 310 and the first and second substantially tubularpressure transmitting mediums 320, 322 may be customizable to helpcontrol the pressure transmitting characteristics of the cell assembly100. The temperature measuring devices 366, 368 may be positionedbetween a distal end of the first substantially tubular pressuretransmitting medium 320 and a proximal end of the second substantiallytubular pressure transmitting medium 322. The proximal electricalcontacts 316 may be proximally disposed adjacent to the proximal end ofthe first substantially tubular pressure transmitting medium 320 and thedistal electrical contacts 318 may be distally disposed adjacent to thedistal end of the second substantially tubular pressure transmittingmedium 322.

A proximal anvil electrical contact 324 may be proximally disposedadjacent to the proximal electrical contacts 316 and may electricallycontact the proximal electrical contacts 316. A distal anvil electricalcontact 326 may be distally disposed adjacent to the distal electricalcontacts 318 and may electrically contact the distal electrical contacts318. The proximal and distal anvil electrical contacts 324, 326 may bemade from steel, titanium, or any other suitable electrically conductivematerial. In an embodiment, as anvils of an ultra-high pressure pressapply a selected pressure to respective faces of the cell assembly 300,one or more of the insulators 362, 364 may flex such that the distal endportion of the can assembly 312 and the proximal end portion of the canassembly 314 electrically contact one another.

The cell assembly 300 may further include a gasket medium 328 generallyin the shape of a cube. The gasket medium 328 may define a receivingspace 330 (FIG. 3B) therethrough that receives the heating elements 302,304, first and second substantially tubular pressure transmitting liners308, 310, insulators 362, 364, can assemblies 312, 314, proximal anddistal electrical contacts 316, 318, and temperature measuring devices366, 368. The receiving space 330 may also at least partially receivethe proximal and distal anvil electrical contacts 324, 326. An end plug332 may be disposed in an opening 334 defined by the proximal anvilelectrical contact 324 and an end plug 336 may be disposed in an opening338 (FIG. 3B) defined by the distal anvil electrical contact 326.Similar to plugs 132, 136, the end plugs 332 and 336 may comprise anysuitable gasket material or any other suitable material.

FIGS. 4A and 4B are cross-sectional and exploded isometric views,respectively, of another embodiment of a cell assembly 400. The cellassembly 400 has many of the same components and features that areincluded in the cell assemblies 100, 300 of FIGS. 1A-3B. Therefore, inthe interest of brevity, the components and features of the cellassembly 100, 300, and 400 that correspond to each other have beenprovided with identical reference numbers, and an explanation thereofwill not be repeated. However, it should be noted that the principles ofthe cell assembly 400 may be employed with any of the embodimentsdescribed in relation to FIGS. 1A-3B and vice versa.

The cell assembly 400 may include one or more resistance heatingelements such as heating element 404. Like the heating elements of cellassemblies 100 and 300, the heating element 404 may comprise graphite orother suitable material. A pressure transmitting medium (e.g.,comprising salt, salt and graphite, etc.) such as a first and secondsubstantially tubular pressure transmitting medium 420 and 422 may bedisposed distal and proximal the heating element 404.

In an embodiment, the heating element 404 may divide the cell assembly400 into two chambers that receive can assemblies 412 and 414. The canassemblies 412, 414 may be configured similar to can assemblies 112,114. For example, each can assembly 412 and 414 may include acorresponding substrate 412A and 414A (e.g., cobalt-cemented tungstencarbide substrate) and a corresponding volume of diamond particles 412Band 414B. As shown, heating element 404 may be positioned in proximityto the volume of diamond particles 412B of can assembly 412 and thevolume of diamond particles 414B of the can assembly 412. A proximalsurface of heating element 404 may be generally opposing a distal endsurface of the can assembly 412. In an embodiment, the proximal surfaceof the heating element 404 may be generally parallel the distal endsurface of the can assembly 412. Similarly, a distal surface of heatingelement 404 may be generally opposing a proximal end surface of canassembly 414. In an embodiment, the distal surface of the heatingelement 404 may be generally parallel the proximal end surface of canassembly 414.

Insulators may be disposed between heating element 404 and canassemblies 412, 414. For example, an insulator disc 465 may be disposedbetween a proximal end surface of can assembly 414 and the heatingelement 404. An insulator ring 463 may be disposed between a distal endsurface of can assembly 412 and the heating element 404. Insulators 463,465 may comprise mica and/or any other suitable material.

As shown in FIG. 4A, the diamond particles 412B, 414B within therespective can assemblies 412, 414 may be positioned toward and near theheating element 404 or the heating element 104 may be positioned betweenthe diamond particles 412B and the diamond particles 414B. Accordingly,the heating element 404 may be configured to heat the diamond particles412B and/or the diamond particles 414B before heating the substrate 412Aand/or the substrate 414A. For example, in an embodiment, at least aportion of heat generated by the heating element 404 may first passthrough the diamond particles 412B or diamond particles 414B beforereaching the distal end region of the substrate 412A or the proximal endregion of the substrate 414A. Such a configuration may help create adesired thermal gradient near the heating element 404 and the diamondparticles 412B, 414B, thus requiring less time and/or energy to sinterthe diamond particles 412B, 414B. Moreover, such a configuration mayallow the heating element 404 to heat both the diamond particles 412Band the diamond particles 114B at substantially the same time,simultaneously, or nearly simultaneously.

In an embodiment, the electrical current pathway may bypass the canassemblies 412, 414 and pass directly through the heating element 404.For example, the cell assembly 400 may include side electrical contacts440, 442 that electrically contact the heating element 404. In anembodiment, the first side electrical contact 440 may extend generallyperpendicular to a longitudinal axis of the cell assembly 400 and mayelectrically contact a proximal portion of the heating element 404 andmay include a disc-like portion 441 that is positioned within thecentral opening of the insulator ring 463. The second side electricalcontact 442 may be generally opposite the first side electrical contact440. The second side electrical contact 442 may electrically contact adistal portion of the heating element 404 and may include a ring-likeportion 443. In an embodiment, the insulator 465 may be positionedwithin a central opening of the ring-like portion 443 of the second sideelectrical contact 442. The first and second side electrical contacts440, 442 may each comprise a suitable electrically conductive andtemperature-resistant material. For example, side-electrical contacts440 and 442 may comprise steel, titanium, molybdenum, TZM molybdenummetal alloys, combinations thereof, or any other suitable electricallyconductive material.

In the illustrated embodiment, the disc-like portion 441 of the firstside electrical contact 440 may include an outer diameter which is lessthan an inner diameter of the ring-like portion 443 of the second sideelectrical contact 442. The disc-like portion 441 of the first sideelectrical contact 440 may be positioned over the central opening of thering-like portion 443 of the second side electrical contact 442. Asdescribed above in relation to FIGS. 1E and 1F, by changing the size ofdisc-like portion 441 and/or ring-like portion 443, position ofdisc-like portion 441 and/or ring-like portion 443, and/or direction ofcurrent flow between the disc-like portion 441 of the first sideelectrical contact 440 and the ring-like portion 443 of the second sideelectrical contact 442 relative to the heating element 104, thedirection and/or location of current flow through the heating element404 may be varied and/or controlled. Consequently, the size, intensity,and heating pattern of the heating element 404 may also be localized,varied, and/or controlled to influence the heating characteristics ofthe diamond particles 412B, 414B.

In an embodiment, the first and second side electrical contacts 440, 442may be positioned between a distal end of the first substantiallytubular pressure transmitting medium 420 and a proximal end of thesecond substantially tubular pressure transmitting medium 422. In anembodiment, at least one of the first and second substantially tubularpressure transmitting mediums 420, 422 may include one or more recessesconfigured to receive the first and second side electrical contacts 440,442. In addition, the first and second side electrical contacts 440, 442may extend between the heating element 404 and side portions of thegasket medium 428. In an embodiment, a first side anvil electricalcontact 445 may electrically contact an end region of the first sideelectrical contact 440 associated with one of the side portions of thegasket medium 428. Similarly, a second side anvil electrical contact 447may electrically contact an end region of the second side electricalcontact 442 associated with another side portion of the gasket medium428.

The cell assembly 400 may further include the gasket medium 428 in theshape of a cube. As shown, the gasket medium 428 may comprise a two-partgasket medium including a first portion 428A and a second portion 428B.The first and second portions 428A, 428B may each include an end wall, aside wall connected to the end wall, and an interior space 430 (FIG. 4B)at least partially defined by the end wall and the side wall with anedge of the side wall defining an opening into the interior space. Eachportion 428A, 428B may further include a length defined between theopening and the end wall. In an embodiment, the first and secondportions 428A, 428B may be substantially similar. In other embodiments,the first and second portions 428A, 428B may exhibit differentconfigurations. For example, in an embodiment, the length of the firstportion 428A may greater or less than the length of the second portion428B. In another embodiment, the interior space of one of the first andsecond portions 428A, 428B may be larger or small than the other.

The interior spaces 430 of the first and second portions 428A, 428B maycollectively define a receiving space that receives the heating element404, insulators 463 and 465, and the first and second substantiallytubular pressure transmitting medium 420, 422. The receiving space 430may also at least partially receive the first and second side electricalcontacts 440, 442. In an embodiment, at least one of the first or secondportions 428A, 428B of the gasket medium 428 may include one or morerecesses configured to receive the first and second side electricalcontacts 440, 442.

While side electrical contacts 440, 442 are shown exhibiting wire-likeconfigurations including disc-like and ring-like portions, in otherembodiments, the side electrical contacts 440, 442 may exhibit differentconfigurations. For example, one or more of the side electrical contacts440, 442 may exhibit a disc-like, annular, rectangular configuration, orother suitable configuration. In other embodiments, one or more of theside electrical contacts 440, 442 may exhibit a wire-like or athin-strip configuration including a square end member or the end membermay be omitted. Further, while two side electrical contacts areillustrated, it will be appreciated that the cell assembly 400 mayinclude any suitable number of side electrical contacts in addition toor in alternative to the proximal and distal end electrical contacts.

In other embodiments, cell assemblies may be configured for asymmetricheating or to apply more or less heat in a selected location or may beconfigured to generate heat proximate to a nonplanar superabrasivepowder layer or diamond volume. For example, FIGS. 5A and 5B arecross-sectional and exploded isometric views, respectively, of anembodiment of a cell assembly 500. The cell assembly 500 has many of thesame components and features that are included in the cell assemblies100, 300, and 400 of FIGS. 1A-4B. Therefore, in the interest of brevity,the components and features of the cell assembly 100, 300, 400, and 500that correspond to each other or are otherwise similar have beenprovided with identical reference numbers, and an explanation thereofwill not be repeated. However, it should be noted that the principles ofthe cell assembly 500 may be employed with any of the embodimentsdescribed in relation to FIGS. 1A-4B and vice versa.

The cell assembly 500 may include a first substantially tubularresistance heating element 502 defining a passageway 502A (FIG. 5B) anda second disc-like resistance heating element 504. The heating element502 may include a proximal end region having a proximal mouth and adistal end region having a distal mouth, with the passageway 502Aextending between the proximal mouth and the distal mouth. A pressuretransmitting medium, such as a first tubular liner 508, a cap 510, and adisc 511 may be disposed in the passageway 502A of the heating element502. The cap 510 may be positioned proximal the first tubular liner 508and the disc 511 may be positioned distal the first tubular liner 508.In an embodiment, the cap 510 may include a distal opening, a proximalbase portion, and conical receiving space at least partially definedbetween the distal opening and the proximal base portion. The heatingelement 504 may be positioned toward the proximal closed end of the cap510. Cap 510, disc 511, and liner 508 may comprise salt, salt andgraphite, or another suitable material.

The first liner 508 and the cap 510 may receive a can assembly 512. Thecan assembly 512 may include a cup 512C defining a generally concaverecess, a volume of diamond particles 512B positioned within the openingof the cup 512C, and a corresponding substrate 512A including a proximalend surface. The recess of the cup 512C and/or the proximal end surfaceof the substrate 512A may be shaped and/or configured to form the volumeof diamond particles 512B in a variety of different shapes and/orconfigurations. For example, in the illustrated embodiment, the recessof the cup 512C and the proximal end surface of the substrate 512A maycollectively be configured to form or shape the volume of diamondparticles 512B into a generally dome-like shape. In other embodiments,the recess of the cup 512C and/or the proximal end surface of thesubstrate 512A may be shaped and/or configured to form or shape thevolume of diamond particles 512B into a convex shape, a tooth-likeshape, a triangular-like shape, a chisel-like shape, a plurality ofprotrusions, a plurality of nubs, combinations thereof, or any othersuitable shape and/or configuration. The cup 512C may be positionedwithin the cap 510. As shown, the heating element 502 may generallysurround the diamond particles 512B and the substrate 512A, while theheating element 504 may be positioned toward the diamond particles 512Bof the can assembly 512. The heating element 504 may include a distalsurface generally opposing a proximal end surface of the can assembly512. In some embodiments, heating element 502 may radiate heat towardthe center of the heating element 502 to heat both the diamond particles512B and the substrate 512A, while heating element 504 may generate atleast some heat near a tip portion of the diamond particles 512B withinthe cup 512C. Thus, the heating elements 502 and/or 504 may shift orinfluence the heating pattern within the diamond particles 512B. Forexample, such a configuration may allow heating of the tip portion ofthe diamond particles 512B without overheating the outer radial portionof the diamond particles 512B within the cup 512C.

A proximal anvil electrical contact 524 may be disposed adjacent to theheating element 504 and may electrically contact the heating element504. A distal anvil electrical contact 526 may be disposed adjacent tothe distal end region of the heating element 502 and may electricallycontact the heating element 502. The proximal and distal anvilelectrical contacts 524, 526 may comprise titanium, steel, zirconium,molybdenum, TZM molybdenum metal alloys, combinations thereof, or anyother suitable electrically conductive material. For example, in anembodiment, at least one of the proximal anvil electrical contact 524 orthe distal anvil electrical contact 526 may comprise a titanium and/orzirconium cup. Such a configuration may help reduce heat transfer out ofthe ends of the cell assembly 500 due to the lower thermal conductivityof titanium and/or zirconium compared to steel and/or help reduce thethickness of the anvil electrical contacts 524, 526. For example, in anembodiment, at least one of the proximal anvil electrical contact 524 orthe distal anvil electrical contact 526 may exhibit a thickness of about0.01 inches, about 0.02 inches, about 0.03 inches, about 0.04 inches,about 0.05 inches, about 0.06 inches, about 0.07 inches, about 0.08inches or about 0.09 inches. In other embodiments, at least one of theproximal anvil electrical contact 524 or the distal anvil electricalcontact 526 may exhibit a thickness between about 0.01 inches and about0.1 inches; about 0.02 inches and 0.09 inches; about 0.03 inches andabout 0.08 inches; about 0.04 inches and about 0.07; about 0.01 inchesand about 0.05 inches; or about 0.02 inches and about 0.04 inches. Inother embodiments, the thickness of at least one of the proximal anvilelectrical contact 524 or the distal anvil electrical contact 526 may belarger or smaller.

In other embodiments, at least one of the proximal and/or distal anvilelectrical contacts 524, 526 may exhibit a ring-like configuration orany other suitable configuration. In an embodiment, a proximal annularinsulator 562 may be interposed between the proximal anvil electricalcontact 524 and the heating element 504. The proximal insulator 562 maycomprise any suitable insulative material, such as mica.

The cell assembly 500 may further include a gasket medium 528 generallyin the shape of a cube. The gasket medium 528 may define a receivingspace 530 (FIG. 5B) that receives the heating elements 502, 504, a firsttubular liner 508, a cap 510, and a disc 511, and can assembly 512. Thereceiving space 530 may also at least partially receive the proximal anddistal anvil electrical contacts 524 and 526. A plug 532 may be disposedin an opening (not shown) defined by the proximal anvil electricalcontact 524 and a gasket medium plug 536 may be disposed in an opening538 defined by the distal anvil electrical contact 526. The gasketmedium 528 and the plugs 532 and 536 may comprise any suitable gasketmaterial or any other suitable materials, without limitation.

FIG. 6 is a cross-sectional view of a cell assembly 600 according toanother embodiment. The cell assembly 600 has many of the samecomponents and features that are included in the cell assemblies 100,300, 400, and 500 of FIGS. 1A-5B. Therefore, in the interest of brevity,the components and features of the cell assembly 100, 200, 300, 400,500, and 600 that correspond to each other or are otherwise similar havebeen provided with identical reference numbers, and an explanationthereof will not be repeated. However, it should be noted that theprinciples of the cell assembly 500 may be employed with any of theembodiments described in relation to FIGS. 1A-5B and vice versa.

The cell assembly 600 may include a pressure transmitting medium such asa cap 610 and cup liner 608 positioned distal to the cap 610. The cap610 may include a distal opening, a proximal base portion, and aconcaved receiving space at least partially defined between the distalopening and the proximal base portion. In an embodiment, the proximalbase portion of the cap 610 may include an opening extending between thereceiving space and a proximal surface. In the illustrated embodiment,the cup liner 608 may exhibit a generally can-like configuration. Cap610 and/or cup liner 608 may comprise salt, salt and graphite, oranother suitable material.

The cell assembly 600 may also include one or more resistance heatingelements, such as heating element 604. Like the heating elements of cellassembly 100, the heating element 604 may comprise graphite or any othersuitable material. As shown, the heating element 604 may be positionedwithin the receiving space of the cap 610.

The cup liner 608 and the cap 610 may receive a can assembly 612. Thecan assembly 612 may include a proximal cup 612C defining a generallyconcave or bowl-like recess, a volume of diamond particles 612Bpositioned within the recess of the cup 612C, and a correspondingsubstrate 612A positioned within a distal portion 612D configured as agenerally cylindrical can. The recess of the cup 612C may be shapedand/or configured to form the volume of diamond particles 612B in avariety of different shapes and/or configurations. For example, in theillustrated embodiment, the recess of the cup 612C may be configured toform or shape the volume of diamond particles 612B into a generallydome-like shape. In other embodiments, the recess of the cup 612C may beshaped and/or configured to form or shape the volume of diamondparticles 612B into another nonplanar suitable shape and/orconfiguration.

The heating element 604 may be positioned within the recess of the cap610 and electrically contacting the cup 612C. In an embodiment, theheating element 604 may exhibit a generally bowl-like shape configuredto generally conform to the peripheral shape of the cup 612C. While theheating element 604 is shown exhibit a generally bowl-like shape, theheating element 604 may exhibit a generally cylindrical shape, agenerally cube shape, an asymmetrical shape, or any other suitableshape.

As shown, the heating element 604 may be positioned to generally coverthe area of the cup 612C containing the volume of diamond particles 612Bto be sintered. Thus, heat generated by the heating element 604 may heatthe volume of diamond particles 612B in a generally uniform pattern. Inaddition, because of the position of the heating element 604, heatgenerated by the heating element 604 may be targeted at the volume ofdiamond particles 612B. Such a configuration may allow cobalt (oranother suitable catalyst) from the substrate 612A to sweep from aregion adjacent to the volume of diamond particles 612B into theinterstitial regions between the diamond particles 612B during sinteringin a more uniform fashion than another HPHT processes in which theentirety of a can assembly is heated.

The cell assembly 600 may include one or more electrical contacts toform at least a part of an electrical current through the cell assembly600. For example, in the illustrated embodiment, the cell assembly 600may include a proximal electrical contact 616 disposed generallyadjacent to a proximal surface of the heating element 604 andelectrically contacting a periphery of the heating element 604. In anembodiment, the proximal electrical contact 616 may exhibit a generallybowl-like shape configured to generally correspond to the shape of theheating element 604. As shown, a concave recess in the proximalelectrical contact 616 may receive at least a portion of the heatingelement 604. A distal generally cylindrical electrical contact 618 maybe disposed generally adjacent to a distal end of the distal portion612D of the can assembly 612 and may electrically contact a periphery ofthe can assembly 612D. The distal electrical contact 618 may extendthrough an opening formed in a distal portion of the can liner 608.While distal electrical contact 618 is illustrated configured as agenerally cylindrical member, in other embodiment, the distal electricalcontact 618 may be configured as a button-like member, a wire-likemember, a tubular member, combinations thereof, or any other suitabletype of electrical contact. The electrical contacts 616, 618 may be madefrom titanium, a titanium alloy, or other suitable electricallyconductive and temperature-resistant material. Moreover, the proximaland distal electrical contacts 616, 618 may include one, three, five, orany other suitable number of electrical contacts.

A proximal anvil electrical contact 624 may be proximally disposedadjacent to the proximal electrical contact 616 and may electricallycontact the proximal electrical contact 616. The proximal anvilelectrical contact 624 may exhibit any suitable shape. For example, inthe illustrated embodiment, the proximal anvil electrical contact 624may exhibit a generally tapered shape having a distal concaved recessconfigured to generally to conform to the shape of the proximalelectrical contact 616. The proximal anvil electrical contact 624 may bemade from steel, titanium, or any other suitable electrically conductivematerial. In other embodiments, cell assembly 600 may include a distalanvil electrical contact distally disposed adjacent to the distalelectrical contact 618 that electrically contacts the distal electricalcontact 618.

The cell assembly 600 may further include a gasket medium 628 generallyin the shape of a cube. The gasket medium 628 may define a receivingspace that receives at least the heating element 604, the can assembly612, the proximal electrical contact 616, and pressure transmittingmediums 608, 610. The receiving space may also at least partiallyreceive the proximal anvil electrical contact 624 and the distalelectrical contact 618. A plug 632 may be positioned at the proximal endof the gasket medium 628. At least a portion of the proximal anvilelectrical contact 624 may extend through a formed in the plug 632. Aplug 636 may be positioned at the distal end of the gasket medium 628.As shown, at least a portion of the distal electrical contact may extendthrough a hole formed in the plug 636. The gasket medium 628 and theplugs 632 and 636 may comprise any suitable gasket material or any othersuitable materials, without limitation.

In an embodiment, an electrical current may pass from an anvil (shown inFIG. 2) to the proximal anvil contact 624. From the proximal anvilcontact 624, the electrical current may pass to the proximal electricalcontact 616 and then to the heating element 604. As discussed above, theheating element 604 may convert electrical energy into heat to heat thecontents of the can assembly 612. From the heating element 604, theelectrical current may then pass to the can assembly 612. From the canassembly 612, the electrical current may pass through the distalelectrical contact 618 and out the cell assembly 600. In otherembodiments, the proximal anvil contact 624 may be omitted andelectrical current may pass directly from the anvil to the proximalelectrical contact 616.

Thus, the cell assembly 600 may be configured to provide heating orgenerally generate heat near the volume of diamond particles 612B withinthe can assembly 612. Such a configuration may allow higher sinteringtemperatures because the heating element 604 can provide heating to thevolume of diamond particles 612B without overheating other portions ofthe can assembly 612.

While various aspects and embodiments have been disclosed herein, otheraspects and embodiments are contemplated. The various aspects andembodiments disclosed herein are for purposes of illustration and arenot intended to be limiting. Additionally, the words “including,”“having,” and variants thereof (e.g., “includes” and “has”) as usedherein, including the claims, shall be open ended and have the samemeaning as the word “comprising” and variants thereof (e.g., “comprise”and “comprises”).

What is claimed is:
 1. A cell assembly for use in a high-pressure cubicpress, comprising: a first can assembly that holds a first diamondvolume, the first can assembly including a first end surface inproximity to the first diamond volume, the first can assembly includingrefractory metal that is in direct contact with the first diamondvolume; a second can assembly that holds a second diamond volume, thesecond can assembly including second end surface in proximity to thesecond diamond volume, the second can assembly including refractorymetal that is in direct contact with the second diamond volume; at leastone heating element positioned between the first can assembly and thesecond can assembly, the at least one heating element including a lengthand a thickness, wherein the length is greater than the thickness, theat least one heating element including a major surface generallyopposing and positioned adjacent to the first end surface of the firstcan assembly and adjacent to the second end surface of the second canassembly, the at least one heating element positioned and configured toheat the first diamond volume and the second diamond volume; at leastone pressure transmitting medium including salt and extending about thefirst can assembly and the second can assembly, wherein a cross-sectionof the cell assembly includes the first can assembly and the second canassembly being positioned laterally nearest to the at least one pressuretransmitting medium; and a gasket medium defining a receiving space thatreceives the first can assembly, the second can assembly, the at leastone heating element, and the at least one pressure transmitting mediumtherein, wherein a cross-section of the cell assembly includes the atleast one pressure transmitting medium being positioned laterallynearest to the gasket medium.
 2. The cell assembly of claim 1, whereinthe at least one heating element comprises a disc, a washer, or anannular ring having a center generally aligned with a center of thediamond volume.
 3. The cell assembly of claim 1, wherein the majorsurface of the at least one heating element is generally parallel to atop or bottom surface of a first substrate that is positioned adjacentto the first diamond volume.
 4. The cell assembly of claim 3, whereinthe major surface of the at least one heating element is adjacent to thediamond volume.
 5. The cell assembly of claim 1, wherein the at leastone heating element comprises a graphite disc, a washer, or an annularring.
 6. The cell assembly of claim 5, wherein the first diamond volumeincludes a first plurality of diamond particles positioned adjacent to afirst substrate and the second diamond volume includes a secondplurality of diamond particles positioned adjacent to a secondsubstrate, and wherein the graphite disc, the washer, or the annularring is positioned between the first can assembly and the second canassembly.
 7. The cell assembly of claim 6, further comprising: aproximal electrical contact electrically contacting the first canassembly at a proximal region thereof; and a distal electrical contactelectrically contacting the second can assembly at a distal regionthereof.
 8. The cell assembly of claim 6, further comprising: a firstside electrical contact electrically contacting a proximal surface ofthe graphite disc, the washer, or the annular ring; and a second sideelectrical contact electrically contacting a distal surface of thegraphite disc, the washer, or the annular ring.
 9. The cell assembly ofclaim 1, further comprising: a thermocouple near the at least oneheating element, the thermocouple configured to measure a temperature ofthe at least one heating element.
 10. The cell assembly of claim 1,further comprising: a first heating element including a distal surfaceadjacent to first end surface of the first can assembly; and a secondheating element including a proximal surface adjacent to the second endsurface of the second can assembly.
 11. The cell assembly of claim 1,wherein the at least one of the first can assembly or the second canassembly comprises an open top cup including a receiving space thatholds the first or second diamond volume and at least a portion of asubstrate.
 12. The cell assembly of claim 1, wherein the at least onepressure transmitting medium comprises a substantially tubular linerincluding salt.
 13. The cell assembly of claim 1, wherein the gasketmedium comprises at least one gasket material selected from a groupconsisting of a naturally occurring gasket material and a syntheticgasket material.
 14. The cell assembly of claim 1, wherein the first orsecond diamond volume comprises diamond particles or a preformedpolycrystalline diamond volume.
 15. A cell assembly for use in ahigh-pressure cubic press, comprising: a first can assembly that holds afirst diamond volume positioned adjacent to a first substrate, the firstcan assembly including a distal end and a proximal end, the first canassembly including refractory metal that is in direct contact with thefirst diamond volume; a second can assembly that holds a second diamondvolume positioned adjacent to a second substrate, the first can assemblyincluding a distal end and a proximal end, the second can assemblyincluding refractory metal that is in direct contact with the seconddiamond volume; a heating element positioned between the first diamondvolume and the second diamond volume, in a manner that a distal end ofthe heating element is positioned adjacent to the proximal end of thefirst can assembly, and a proximal end of the heating element ispositioned adjacent to the distal end of the second can assembly, theheating element positioned and configured to heat at least one of thefirst diamond volume or the second diamond volume; a pressuretransmitting medium including salt and extending about at least one ofthe first can assembly or the second can assembly, wherein across-section of the cell assembly includes the first can assembly andthe second can assembly being positioned laterally nearest to the atleast one pressure transmitting medium; and a gasket medium defining areceiving space that receives the first can assembly, the second canassembly, the heating element, and the pressure transmitting mediumtherein, wherein a cross-section of the cell assembly includes thepressure transmitting medium being positioned laterally nearest to thegasket medium.
 16. The cell assembly of claim 15, wherein the heatingelement is a first heating element, and further comprising: a secondheating element positioned between the first diamond volume and thesecond diamond volume, wherein the second heating element is configuredto heat at least one of the first diamond volume or the second diamondvolume.
 17. The cell assembly of claim 16, further comprising: aninsulator positioned between the first heating element and the secondheating element.
 18. A method, comprising: disposing at least one afirst can assembly and a second can assembly within at least onepressure transmitting medium that extends about the at least one firstcan assembly and the second can assembly, the at least one each of thefirst can assembly and the second can assembly including an end surfaceand holding a diamond volume, the at least one each of the first canassembly and the second can assembly including refractory metal that isin direct contact with the diamond volume; positioning a substantiallyplanar heating element adjacent to the end surface of the at least onecan assembly between the first can assembly and the second can assemblysuch that the heating element heats the diamond volumes of therespective first can assembly and second can assembly when a current ispassed therethrough, the heating element including a length and athickness, wherein the length is greater than the thickness; and sealingthe diamond volumes of the respective first can assembly and second canassembly in the at least one can assembly, the heating element, and theat least one pressure transmitting medium within a gasket medium to forma cell assembly, wherein a cross-section of the cell assembly includesthe at least one can assembly being positioned laterally nearest to theat least one pressure transmitting medium, and the pressure transmittingmedium being positioned laterally nearest to the gasket medium.
 19. Themethod of claim 18, further comprising: electrically contacting a firstelectrical contact to the heating element at a proximal surface thereof;and electrically contacting a second electrical contact to the heatingelement at a distal surface thereof.
 20. The cell assembly of claim 1,wherein the gasket medium continuously extends along opposing sides ofthe at least one can assembly.